2. Field of the Invention
This invention relates to a device for monitoring the dispensing of medication to patients. More particularly it relates to a system for accurately detecting drug dispensing events.
2. Description of the Prior Art
A variety of devices and methods have been described for controlling, noting, and keeping track of dispensation of medicines to patients. These devices range from simple mechanical checklist systems, through pill containers equipped with alarm clocks and the like and pill containers having timer-controlled latching devices which regulate the patient's access to medication. Some typical examples of these devices include the timed medication dispenser described by Roy J. Machamer in U.S. Pat. No. 4,382,688 which shows a medical dispenser having an electronic reminder to take the medication it contains. In this device the electronic reminder is disabled when the user takes the medication. In U.S. Pat. No. 4,448,541, Jonathan D. Wirtschafter describes a magnetically responsive switch device which is activated when a medication dispenser is opened so as to give an indication of the drug dispensing event. U.S. Pat. No. 4,367,955 of Donald H. Ballew shows a combined timer and container for dispensing medications wherein the container and its lid coact to initiate the timer cycle upon interengagement of the cap and container. U.S. Pat. No. 4,034,757 of Glover shows a device having two switches, each of which must be activated simultaneously to register a drug delivery event.
The foregoing patents are merely representative. Other background patents relating to medication dispensers include for example U.S. Pat. Nos. 3,369,697 of Glucksman et al.; 3,395,829 of Cogdell et al.; 3,651,984 of Redenback; 3,722,739 of Blumberg; 3,762,601 of McLaughlin; 3,815,780 of Bauer; 3,911,856 of Ewing; 3,917,045 of Williams; 3,968,900 of Stambuk; 3,998,356 of Christensen; 4,207,992 of Brown; 4,223,801 of Carlson; 4,258,354 of Carmon et al.; 4,275,384 of Hicks et al.; 4,360,125 of Martindale et al.; 4,361,408 of Wirtschafter; 4,382,688 of Machamer; 4,419,016 of Zoltan; 4,448,541 Wirtschafter; 4,473,884 of Behl; 4,483,626 pof Nobel; 4,490,711 of Johnston; 4,504,153 of Schollmeyer et al. and 4,526,474 of Simon.
In the case of devices with which it is desired to monitor access to a multidose drug container it is of importance to be able to identify true access events and distinguish them from false events. A true event would include opening the container, removing a pill or other medicament and then closing the container. A false event could include leaving the container open and repeatedly removing pills or, in the case of the not-sure-handed, repeated attempts at reinstalling the cap after a single removal of a drug or dropping the closed container, thereby actuating the open-close switch by means of the force of impact.
It is an object of this invention to provide a detection system which will be capable of identifying true drug removal events and discriminating them from these false events.
It is important that a device capable of electronically identifying and recording drug dosing information be constructed in a manner which is sturdy and reliable. It is also important that the construction be such as to minimize even inadvertent contact between the medication contained in the device and the various electronic elements which note and record the dosing information. This avoids contamination of the drug by contact with the electronic component, on the one hand, and interference with the proper functioning of the electronics by contact with the drug, on the other. The construction should also minimize cost and advantageously permit reuse of expensive electronic components. To these ends, it is a further object of this invention to provide a device for measuring and recording drug dosing information which physically separates the majority of the electronic components from the drug storage chamber. It is also an object of this invention to provide a device in which major electronic components can be recycled.